Malignant hypertension is induced using Goldblatt clamps to the renal arteries of Rhesus monkeys. Our overall objectives are to clarify our understanding of the evolution and resolution of retinopathy and choroidopathy resulting from malignant hypertension using fundus photography, fluorescein angiography, light and electronmicroscopy. We plan to: 1. Describe topography, evolution and repair of specific retinal and choroidal lesions both of the vascular system and of the parenchyma. 2. Investigate permeability changes of retinal and choroidal vasculatures using horseradish peroxidase as tracer.